creators_name: Casagrande, Marion creators_name: David, Christophe creators_name: Etienne, Catherine creators_name: Makowski, David creators_name: Valantin-Morison, Muriel creators_name: Jeuffroy, Marie-Hélène type: conference_item datestamp: 2008-09-23 lastmod: 2009-08-20 14:37:39 metadata_visibility: show title: Agronomic and environmental factors explaining Grain Protein Content variability in organic winter wheat ispublished: pub subjects: 3cereals full_text_status: public keywords: organic winter wheat, Grain Protein Content, limiting factors, diagnosis abstract: A regional agronomic diagnosis was implemented to identify factors responsible for low values of Grain Protein Content (GPC) in a network of 35 organic winter wheat fields in South-Eastern France. The influence of water nutrition, radiation and temperature, weed density at flowering, nitrogen (N) status of crop at flowering and variety type were studied. Two statistical methods were used successively: classical linear regression and a mixing model approach based on a weighted sum of all possible linear combinations of explanatory variables. GPC was significantly related to variety type, crop N status and weed density. An analysis of variance showed that weed density was related to soil type and nitrogen supply. date: 2008 date_type: published refereed: yes citation: Casagrande, Marion; David, Christophe; Etienne, Catherine; Makowski, David; Valantin-Morison, Muriel and Jeuffroy, Marie-Hélène (2008) Agronomic and environmental factors explaining Grain Protein Content variability in organic winter wheat. Cultivating the Future Based on Science: 2nd Conference of the International Society of Organic Agriculture Research ISOFAR, Modena, Italy, June 18-20, 2008. document_url: http://orgprints.org/11825/1/Casagrande_11825_ed.doc